My Mines and those of My Brother

Naval mines have a tendency to stay largely out of sight, until they suddenly pop up to remind everyone about their existence. This goes both for the weapons themselves, as for their role in the grand scheme of things. The Baltic Sea, always a favourable battlefield for mines, has seen a number of interesting development during the last few weeks.

The most significant is that Estonia announced the procurement of a “significant number” of Finnish naval mines. The version isn’t confirmed, but the main suspect is the Forcit “Blocker“, known in Finnish service under the significantly less awe-inspiring moniker of PM16. The mine in question has a strong claim on the title as the world’s most advanced ground influence mine, and is the result of decades of Finnish (open) research into influence mines. Its characteristics also fit rather well with the description used by the Estonian Defence Forces with regards to how the new mine will change their ways of operating:

We haven’t rehearsed many practical skills with regard to how to submerge them in water lately, I admit, at least not in the way we will be doing it now. And this has changed – there are fewer people, and more computers.

The quote above is made by the Commander of the Estonian Navy, Cdre Jüri Saska, in an interview with the Estonian national broadcaster ERR. In the original TV-interview the footage shown is interestingly of the Finnish naval auxiliary FNS Louhi (999) using a containerised system – presumably the 20-foot Forcit SUMICO able to deploy 12 Blockers – to drop the mines. It is unclear whether this is just B-roll, or whether the deployment shows Estonian tests of the containerised solution. Considering the small number of vessels within the Estonian Navy, the ability to use workboats able to handle 20-foot containers for minelaying would be a significant force multiplier.

For the time being, the Navy operate a single ex-Danish Lindormen-class minelayer, the EML Wambola. The sister EML Tasuja was retired in 2016 when EML Wambola was taken into service, but depending on the source it seems she might still be held in reserve. The 577-ton vessel, roughly corresponding in size to the Finnish Pansio-class, can take approximately 50-60 mines but has mainly seen work as squadron leader to the Navy’s three minehunters which together with it make up the main unit of the small Estonian Navy: the Miinilaevade Divisjon. It will be interesting to see whether the role of the EML Wambola will change, or if a new class of vessels will take on the role as minelayers.

However, while the changes to Estonian doctrine and naval order of battle are interesting, this is a deal of strategic significance which will have caught the attention of people both in Norfolk as well as in St Petersburg. Because a revitalised Estonian minewarfare capability, especially when taken together with the announced decision to procure land-based anti-ship missiles, certainly provide the basis for a 21st century re-run of the 20th century favourite of armchair admirals studying maps of the Baltic Sea: Czar Peter the Great’s Naval Fortress.

Morskaya krepost imperatora Petra Velikogo was what happens when your Navy decides to sail halfway around the world only to get sunk by an up-and-coming naval power. Shortly before WWI, the Russian state started investing heavily in coastal defences to protect the entrance to St Petersburg. Great idea, at least until Estonia and Finland became independent and ran away with most of the heavy fixed guns installed in the half-finished project. The interwar years then saw Finland and Estonia in turn planning how to use these as the backbone in a plan to seal the Gulf of Finland to Soviet shipping, before Estonia was occupied by the Soviets. With the exception of the brief interlude between 1941 and 1944 when Finland and Germany rather successfully bottled up the Soviet Baltic Fleet through a combination of mines, coastal guns, and smaller naval vessels, the Estonian coast spent the rest of the century firstly occupied, and then rather poorly defended. This is now set to change.

Very much in a similar fashion to the situation around Kaliningrad where the (in)famous Suwałki-gap is both a trap and an opportunity for both sides, the waterways from the Gulf of Finland out to the northern parts of the Baltic Sea proper are of serious importance both to NATO as the logistics route to reinforce Estonia and Latvia (either as the last sea-leg for an overland route through Norway and Sweden or as the ports of disembarkation for ships) as well as to Russian planners in a number of different ways. Key among these are not only the military ones, but the route is of great importance to Russian hydrocarbon exports (Ust Luga and Primorsk combined outranking the largest single port for exports, Novorossiysk, which handles basically all of Russia’s Black Sea exports), and the importance of the Gulf of Finland as the route for exports westwards is only set to keep growing. However, by the time one start talking about sea mines, the military considerations will in all likelihood be of greater importance, and here the Gulf of Finland is of both offensive and defensive importance.

Defensively, while Baltiysk is the main base of the Russian Baltic Fleet, it is also isolated from the Russian mainland. As such, keeping a supply line open not only for the Baltic Fleet to be able to shift units between Kronstadt and Baltiysk according to need, but also to be able to supply the rest of Kaliningrad’s military and civilian needs, is of great importance. Offensively, the ability to operate freely in the northern parts of the Baltic Sea proper would allow for cutting off vital supply lines to both Finland and Estonia, as well as seriously threatening key Swedish interests such as the capital Stockholm and surrounding regions.

As opposed to with its Nordic neighbours, Finland hasn’t been as active in advertising increased defence cooperation with Estonia in recent years. Rather, the headlines have been dominated by a number of if not exactly crises, then at least diplomatic grumblings. Part of this is a natural outcome of the rather different lessons drawn by the very different historical outcomes (read: occupation versus Finlandization) the countries experienced following WWII, but it has nonetheless caused friction. Still, once one start digging below the surface, Finnish soldiers have been actively taking part in key Estonian exercises, and the deepened cooperation between democratic countries in Northern Europe has certainly had a positive effect on Finnish-Estonian military cooperation as well.

In any case, with Finland largely being seen as a part of “The West” in Moscow, any Russian aggression would most likely affect Finnish supply lines and cause a quick alignment of Finnish and Estonian interests (read: keeping the northern Baltic Sea free of Russian vessels and aircraft). As such, the prospect of not one but two countries with modern mining capabilities as well as the ability to protect the minefields with long-range anti-ship weaponry will have an effect on the strategic calculations made by the Kremlin. Further to this, while the Gulf of Finland is narrow enough that even modern long-range artillery can cover it from one shore to the other at the narrowest location, but getting an accurate picture of what happens on the other shore might still prove more of a challenge, the prospect of these countries sharing a maritime situational picture and possibly even cooperating on the operational use of the aforementioned systems further tilt the balance. Notable is also that the ability to use ‘smart’ mines means that the risk to civilian shipping is lower, a not insignificant aspect when it comes to the use of naval mines in waters as heavily trafficked as those of the Baltic Sea.

For the Finnish Navy, mines have always featured heavily in their communication, a method of latent suasion for which mines are well suited (and something that will happen to some extent almost by default the minute one start stockpiling them). However, as usual there are significant ambiguity when it comes to the stockpiles, including not only numbers but also exact models in use. Interestingly, the Finnish Navy has during the last year showed a number of the oldest influence mines acquired by the Finnish Navy back in the 80’s being used in exercises, including both practicing their employment as well their search and recovery. Whether this is just by chance or a conscious decision to raise the awareness that there are many arrows in the quiver is an interesting question, but it certainly shows that Finnish minewarfare consists of more than the Hot Dog-dance.

…and in my own Ceterum censeo Carthaginem esse delendam-moment, I will note that there’s further US investment in the Quickstrike-ER. The US Navy has recently placed a 58.3 million USD contract with Boeing for the manufacturing of prototype glide-kits and associated equipment. In essence, the Quickstrike-ER is a JDAM-ER with a dedicated fuse which makes it a sea mine able to deploy at depths of up to 60+ meters (which also happens to match nicely with the depths of the Gulf of Finland). It remains my opinion that the Quickstrike-ER represents the most versatile, effective, and cheapest way of introducing air-launched kinetic effect into the maritime domain for the Finnish Air Force, and that the ability to use a handful of JDAM-ER kitted ‘dumb’ bombs to either resow cleared minefields or to cut strategic narrow waterways in what is a relatively low-risk mission compared to the use of JDAM-ERs in a more traditional ground-combat setting would represent a significant capability addition to Finnish minewarfare.